Abstract

Fertile populations of Dicranella circinata Herzog, a poorly known endemic moss species from southern Chile, were recently found in Chiloé Island. The species was previously known only from the type collection, which consists of just a few sterile plants. The first illustrations of this previously insufficiently known taxon, and the description of its sporophytes, together with new geographical, ecological and morphological data, are here provided. Discussion about the taxonomy and nomenclature of the other southern South American species of Dicranella is also presented. We propose two new combinations for names previously placed in the neglected genus Anisothecium Mitt. [Dicranella elegans (Duby) Larraín, and Dicranella fontana (Herzog) Larraín], and new synonyms for D. aulacocarpa Mont. and for D. pseudorufescens Cardot & Broth.